Heretofore, inorganic glass has long been used as the material for such optical elements as lenses and prisms. In recent years, remarkable advancement has been made in the development of various kinds of organic high molecular polymers. Organic high molecular polymers possessed of properties required of optical elements have also been suggested. Examples are poly methyl methacrylate and polycarbonate.
The properties which are indispensable for a given substance to serve as the material for optical elements are excellent optical properties such as high refractive index, transparency and homogeneity as well as high degree of hardness.
The known organic high molecular polymers mentioned above are inferior in several points, particularly in refractive index and other optical properties, to inorganic glass. Under the circumstances, therefore, need is acutely felt for perfection of an organic high molecular polymer which is possessed of satisfactory optical properties.
It is a primary object of this invention to provide a novel polymer of one or more metal salts of itaconic acid monoester possessed of excellent optical properties such as high refractive index and transparency. Another object of this invention is to provide a copolymer of the metal salt of itaconic acid monoester with a vinyl monomer, possessed of excellent optical properties such as high refractive index and transparency.
Still another object of the present invention is to provide a process for producing the said polymer by heating a polymerizable ingredient which is a mixture of a polymerization catalyst and a monomer.
Yet another object of the present invention is to provide a process for producing the said polymer by means of irradiation polymerization.